Volatile liquid anesthetics are known in the art and include by way of example halothane, trichloroethylene and ether derivatives including enflurane, fluroxene, methoxyflurane, and isoflurane.
The aforementioned inhalation anesthetics overcome many of the limitations inherent in earlier agents such as chloroform and ether. These anesthetics act rapidly, have minimal or no toxicity, and are non-flammable. Despite this considerable progress, one limitation continues to be the rate at which recovery from anesthesia occurs. Although recovery is rapid, it is less rapid than might be desired, especially for patients who return home on the day of surgery (outpatient surgery).
The compound employed in the composition of the present invention, 2-(difluoromethoxy)-1,1,1,2-tetrafluoroethane or CHF.sub.2 OCHFCF.sub.3, is disclosed in Example XXI of Russell et al., U.S. Pat. No. 3,897,502, which is directed to processes for making fluorinated ethers to prepare pastes and dispersions of fluorine-containing olefins, waxes to provide coatings, and degreasing agents. Furthermore, the Russell et al. patent states that some of the poly-fluoro containing products which can be made by the methods disclosed in the patent are agents for producing anesthesia in anesthetic-susceptible, air-breathing mammals.
Applicants have found that the compound of the present invention is an effective anesthetic and exhibits unexpectedly rapid induction and recovery.
It is therefore an object of the invention to provide methods of inducing and maintaining anesthesia employing an anesthetic compound that is fast acting and affords the patient rapid recovery from anesthesia.
It is a further object of the invention to provide a method of preparing said compounds in quantitative yields.